The Jelling stones are two massive carved granite runestones standing in the churchyard at Jelling, 15km north of Billund. The smaller stone was raised by King Gorm the Old in the early 10th century in honour of his wife Thyra; the larger, more famous stone was erected by their son Harald Bluetooth around 965 AD. Harald's inscription declares that he "made the Danes Christian" — it is the moment of Denmark's conversion recorded in stone, and the closest thing the country has to a founding document. Both stones are UNESCO World Heritage listed.
Around the churchyard stand two enormous burial mounds — the largest Viking-age burial structures in Denmark — and beneath them the foundations of a wooden stave church. The Kongernes Jelling museum (opened 2013) puts all of this in context with well-designed permanent displays covering the Viking Age, the Jelling dynasty, and the rune stone inscriptions. The museum building is sunk into the landscape to avoid obscuring the historic site. The entire complex is free to enter and takes around two hours to see properly. The stones themselves can be viewed at any hour.